Dopamine Drug Leads to New Neurons and Recovery of Function in Rat Model of Parkinson's Disease
Preliminary results of a study conducted by scientists at the Mayo Clinic College of Medicine in Jacksonville, Florida indicate that a drug that mimics the effect of dopamine may also cause stem cells that already exist in the adult brain to turn into dopamine-producing neurons.
Schmalfeldt:If you or someone you know suffers from Parkinson's Disease, you probably recognize the typical symptoms — a shuffling gait, slowness of movement, stiffness, unsteadiness, and tremor. You may not know that the symptoms are caused by the loss of specialized neurons in the brain that produce a nerve-signaling chemical called "dopamine". There has been much excitement — and controversy — surrounding the use of stem cells to replace these lost dopamine-producing neurons. Now, research funded by the National Institute of Neurological Disorders and Stroke at the National Institutes of Health gives hope that one day scientists may be able to capitalize on the promise of stem cells and their ability to transform into other specialized types of cells, without the controversy that comes from outside sources of these cells. Preliminary results of a study conducted by scientists at the Mayo Clinic College of Medicine in Jacksonville, Florida indicate that a drug that mimics the effect of dopamine may also cause stem cells that already exist in the adult brain to turn into dopamine-producing neurons. The drug also led to long-lasting recovery of function in rats suffering from an animal form of Parkinson's Disease. Dr. Diane Murphy, the NINDS program director for the grant that funded the research, said these findings are exciting for several reasons.
Murphy: The traditional treatment is just to replace the dopamine. Of course, with the advent of stem cells in research people have the idea that they could replace those cells by implanting stem cells that had been engineered to turn into dopamine neurons. I think the interesting thing about this study is that they're showing a way to get stem cells that are already in the brain to differentiate and try to become dopaminergic cells. So, the idea there would be that you don't need to have an external source. If these drugs could stimulate those internal neurons to grow and turn into dopamine neurons, that's actually a very exciting idea for therapy.
Schmalfeldt: Researchers are now looking at how different doses of these drugs might affect the growth of new dopamine-producing neurons. Once they identify the most effective dose in animals, researchers may then be able to test comparable doses in humans. They are also carrying out experiments to learn if using drugs that act on other kinds of receptors might stimulate this sort of new neuron growth in patients with Alzheimer's Disease and other neurodegenerative diseases. The study appeared in the July 5th edition of The Journal of Neuroscience. From the National Institutes of Health, I'm Bill Schmalfeldt in Bethesda, Maryland.
About This Audio Report
Reporter: Bill Schmalfeldt
Sound Bite: Dr. Diane Murphy
Topic: Parkinson's Disease